JP2021063131A - Process for maximizing xylene production from heavy aromatics for use in process - Google Patents

Abstract

To provide a process for maximizing xylene production from heavy aromatics.SOLUTION: A method for producing xylenes from a heavy reformate feed includes the steps of: introducing a heavy reformate feed 100 and a hydrogen feed 105 to a dealkylation reactor 10; reacting the heavy reformate feed with hydrogen gas in the presence of a dealkylation catalyst in the dealkylation reactor to produce a dealkylation effluent 110; introducing the dealkylation effluent to a splitter unit 20; separating the dealkylation effluent in the splitter unit; introducing a toluene stream 124 and a C9 aromatics stream 128 obtained and a hydrogen stream 135 into a transalkylation reactor 30; reacting the toluene stream and the C9 aromatics stream in the presence of a transalkylation catalyst to produce a transalkylation effluent 130; and introducing the transalkylation effluent to the splitter unit and separating it.SELECTED DRAWING: Figure 1

Description

Methods and systems for the production of xylene are disclosed. Specifically, methods and systems for the production of xylene from heavy aromatics are disclosed.

The heavy reforming oil may contain more than 90 weight percent (wt%) of aromatics having 8 or more carbon atoms in the aromatic compound. Of the aromatics, less than 10 wt% can be xylene. Traditionally, heavy reforming oils have been blended into the gasoline stream. However, blending has become even more difficult due to the tighter regulations on aromatic content in gasoline.

The market demand factor for para-xylene (p-xylene) continues to rise. Therefore, the conversion of heavy aromatics to p-xylene results in a valuable product stream.

Methods and systems for the production of xylene are disclosed. Specifically, methods and systems for the production of xylene from heavy aromatics are disclosed.

In a first aspect, a method for producing xylene from a heavy modified oil raw material is provided. The method comprises the step of introducing the heavy reforming oil raw material and the hydrogen raw material into a dealkyl reactor. The dealkyl reactor includes a dealkyl catalyst. The heavy reforming oil contains an aromatic hydrocarbon (C9 + aromatic) having 9 or more carbon atoms, and the hydrogen raw material contains hydrogen gas. The present method is a step of reacting the heavy reforming oil raw material with the hydrogen gas in the presence of the dealkyl catalyst in the dealkyl reactor to produce a dealkyl effluent. The dealkylation reactor is at a dealkylation temperature and at a dealkylation pressure, and the dealkylation reactor has a liquid space velocity, a step and a step of introducing the dealkylation effluent into a splitter unit. The dealkylated effluent comprises a light gas, toluene, benzene, mixed xylene, and C9 + aromatics, and the dealkylated effluent is subjected to a light gas stream, toluene stream, benzene stream, in the splitter unit. It further comprises a step of separating into a C9 aromatic stream, a C10 + aromatic stream, and a mixed xylene stream. The light gas stream contains light hydrocarbons and hydrogen, the toluene stream contains toluene, the benzene stream contains benzene, the mixed xylene stream contains mixed xylene, and the C9 aromatic stream is. Includes C9 aromatics, said C10 + aromatic stream comprising C10 + aromatics. The method is a step of introducing the toluene stream, the C9 aromatic stream, and the hydrogen stream into an alkyl exchange reactor, wherein the alkyl exchange reactor comprises an alkyl exchange reaction catalyst, and the hydrogen stream is hydrogen. The alkyl exchange reactor comprises a step of reacting a gas-containing step with the toluene stream and the C9 aromatic stream in the presence of the alkyl exchange reaction catalyst to produce an alkyl exchange reaction effluent. At the alkyl exchange reaction temperature, at the alkyl exchange reaction pressure, the alkyl exchange reactor has a liquid space velocity, a step and a step of introducing the alkyl exchange reaction effluent into the splitter unit, the alkyl. The exchange reaction effluent comprises a light gas, toluene, benzene, mixed xylene, and a C9 + aromatic, and the mixed xylene in the alkyl exchange reaction effluent from the splitter unit as part of the mixed xylene stream. It further comprises a step of separating the alkyl exchange reaction effluent in the splitter unit so that it spills.

In a particular embodiment, the method further comprises introducing the light gas stream into a gas separator and separating the light gas stream into produced hydrogen and a light gas product. In certain embodiments, the method further comprises the step of introducing the benzene stream into the alkyl exchange reactor. In certain embodiments, the method further comprises supplying an additional aromatic stream to the alkyl exchange reactor such that excess toluene for the alkyl exchange reaction is present in the alkyl exchange reactor. In certain embodiments, the dealkylation temperature is between 200 degrees Celsius (° C.) and 500 degrees Celsius. In certain embodiments, the dealkylation pressure is between 5 bar and 40 bar. In certain embodiments, the liquid space velocity in the dealkyl reactor is between 1 / hour (hr ^-1 ) and 10 hr ^-1 . In certain embodiments, the alkyl exchange reaction temperature is between 300 ° C and 500 ° C. In certain embodiments, the alkyl exchange reaction pressure is between 10 bar and 40 bar. In certain embodiments, the liquid space velocity within the alkyl exchange reactor is between ^{0.5 hr -1} and 6 hr ^-1.

In the second aspect, an apparatus for producing xylene from a heavy reforming oil raw material is provided. The apparatus of the present invention comprises a dealkyl reactor configured to convert a heavy reforming oil raw material and a hydrogen raw material in the presence of a dealkyl catalyst to produce a dealkyl effluent, and the dealkyl reactor. A splitter unit fluidly connected to the dealkylated effluent and alkyl exchange reaction effluent through a light gas stream, a toluene stream, a benzene stream, a C9 aromatic stream, a C10 + aromatic stream, and a mixed xylene stream. The splitter unit and the alkyl exchange reactor fluidly connected to the splitter unit, which are configured to separate into the C9 aromatic stream, the toluene stream, and the hydrogen stream, are subjected to an alkyl exchange reaction. It comprises the alkyl exchange reactor, which is configured to be converted into an alkyl exchange reaction effluent under a catalyst.

In certain embodiments, the apparatus of the present invention further comprises a gas separator fluidly connected to the splitter unit such that the gas separator separates the light gas stream into produced hydrogen and a light gas product. It is configured in.

These and other features, aspects, and advantages of the scope of the invention will be better understood by reference to the following description, claims, and accompanying drawings. However, these drawings only describe a portion of the embodiments and therefore should not be determined to limit the scope of the invention and that other equally valid embodiments are acceptable. Please note.

It is a process diagram of one Embodiment of a process.

It is a process diagram of one Embodiment of a process.

It is a process diagram of one Embodiment of a process.

It is a process diagram of one Embodiment of a process.

It is a process diagram of a single reactor system.

It is a process diagram of one Embodiment of a process.

It is a process diagram of one Embodiment of a process.

It is a process diagram of one Embodiment of a process.

It is a process diagram of a process in which a splitter unit does not exist between a dealkylation reactor and an alkyl exchange reactor.

In the accompanying figures, similar components and / or features may have similar symbols.

Although the scope of the devices and methods of the present invention has been described using some embodiments, those skilled in the art will appreciate numerous examples, modifications, and modifications of the devices and methods described herein. , It will be understood that it is within the scope and purpose of the embodiments of the present invention.

Therefore, the described embodiments are described without loss of generality and without imposition of restrictions with respect to this embodiment. Those skilled in the art will appreciate that the scope of the invention includes all possible combinations and uses of the particular features described herein.

As used herein, processes and systems involving three unit systems for mixed xylene production are described. The heavy reforming oil is introduced into the dealkyl reactor. The dealkylated effluent from the dealkylated reactor is introduced into the splitter unit and separated into components of the dealkylated effluent. Toluene and C9 + aromatics from the splitter unit are introduced into the alkyl exchange reactor. If desired, benzene can also be introduced into the alkyl exchange reactor. The alkyl exchange reaction effluent from the alkyl exchange reactor is introduced into the splitter unit and separated into components of the alkyl exchange reaction effluent. The flow flowing out of the splitter unit contains components of the effluent from both the dealkyl and alkyl exchange reactors.

Advantageously, the combination of a dealkylation reactor with another alkyl exchange reactor catalyzes two types of catalysts, a dealkylation reaction catalyst and an alkyl exchange reaction catalyst, or both dealkylation and alkyl exchange reactions. The total amount of xylene produced is improved as compared to a single reactor system containing one type of catalyst capable of exerting. Advantageously, the overall yield is improved by recirculating the alkyl exchange reaction effluent through the splitter unit. This is to minimize the loss of xylene by reducing the amount of benzene produced through the disproportionation of toluene in the alkyl exchange reactor. Within the alkyl exchange reactor, two major reactions take place to form xylene. These reactions are the equilibrium reaction of alkyl exchange between toluene and trimethylbenzene and the equilibrium reaction of toluene disproportionation shown below.

By recirculating benzene, the amount of benzene produced is limited through Reaction 2, the consumption of toluene in Reaction 2 is reduced, and the amount of toluene available for the production of xylene in Reaction 1 is increased.

As used throughout this specification, the "C" and numerical references refer to the number of carbon atoms in the hydrocarbon. For example, C1 refers to a hydrocarbon having one carbon atom and C6 refers to a hydrocarbon having six carbon atoms.

As used throughout this specification, "C9 aromatic" refers to aromatic hydrocarbons having 9 carbon atoms. Examples of C9 aromatic hydrocarbons include methylethylbenzene, trimethylbenzene, and propylbenzene.

As used throughout this specification, "trimethylbenzene" includes the isomers of trimethylbenzene, hemeliten, pseudocumene, and mesitylene, respectively.

As used throughout the present specification, "C10 + aromatic" means an aromatic hydrocarbon having 10 carbon atoms and an aromatic having more than 10 carbon atoms, for example, an aromatic having 11 carbon atoms. It points to hydrocarbons.

As used throughout this specification, "C9 + aromatic" refers to a group of C9 aromatics and C10 + aromatics.

As used throughout this specification, "mixed xylene" refers to one or more of para-xylene (p-xylene), meta-xylene (m-xylene), and ortho-xylene (o-xylene). ..

As used throughout this specification, "dealkylation" refers to a reaction that results in the removal of an alkyl group from one or more reactants.

As used throughout this specification, "alkyl exchange reaction" refers to a reaction that results in the transfer of an alkyl group from one compound to another.

As used throughout this specification, "light hydrocarbon" refers to one or more of methane, ethane, propane, butane, alkanes containing pentane, alkenes, and trace amounts of naphthene, such as cyclopentane, cyclohexane. Point to.

As used throughout this specification, "light gas" refers to one or more of light hydrocarbons, hydrogen, and air.

With reference to FIG. 1, one embodiment of the process for producing mixed xylene is shown. The heavy reforming oil raw material 100 is introduced into the dealkylation reactor 10 together with the hydrogen raw material 105. The heavy reforming oil raw material 100 can contain toluene, mixed xylene, C9 aromatics, and C9 + aromatics. In at least one embodiment, the heavy modified oil feedstock 100 can contain trace amounts of C8 + naphthene and C10 + naphthylene, as well as alkyl derivatives thereof. In at least one embodiment, the heavy modified oil feedstock 100 can contain between 0 wt% and 10 wt% mixed xylene and between 60 wt% and 100 wt% C9 + aromatics. In at least one embodiment, the heavy modified oil feedstock 100 can contain between 0 wt% and 60 wt% toluene. In at least one embodiment, the heavy modified oil feedstock 100 is a mixed xylene between 0 wt% and 10 wt%, toluene between 0 wt% and 60 wt%, and C9 + aromatics between 60 wt% and 100 wt%. And can be contained. In at least one embodiment, the heavy modified oil feedstock 100 contains between 60 wt% and 100 wt% C9 aromatics, but no C10 + aromatics.

The hydrogen raw material 105 can be any flow containing hydrogen gas. The hydrogen source 105 can be a stream of pure hydrogen from a fresh hydrogen source. In at least one embodiment described with reference to FIG. 2, hydrogen gas can be recovered as produced hydrogen 145 from the process in the gas separator 40. A part of the produced hydrogen 145 can be recirculated as a hydrogen raw material 105 and divided so as to be introduced into the dealkyl reactor 10. In at least one embodiment, the hydrogen source 105 can be from a hydrogen source in a refinery and can contain light hydrocarbons.

With reference to FIG. 1 again, the dealkyl reactor 10 can be any type of reactor capable of containing and maintaining the dealkylation reaction. The dealkylation reactor 10 can be a fixed bed reactor or a fluidized bed reactor. The dealkylation temperature in the dealkylation reactor 10 can be between 200 degrees Celsius (° C.) and 500 degrees Celsius. The dealkylation pressure in the dealkylation reactor 10 can be between 5 bar (500 kilopascals (kPa)) and 40 bar (4000 kPa). The liquid space velocity (LHSV) can be between ^{1 / hour (hr -1} ) and 10 hr ^-1.

The dealkylation reactor 10 can include a dealkylation catalyst. The dealkylation catalyst can include any catalyst capable of catalyzing the dealkylation reaction. Examples of dealkylation catalysts include binary functional catalysts as described in US Pat. No. 9,000,247. The dealkyl catalyst can be selected to selectively convert one or more C9 + aromatics during the dealkylation reaction over anything else. The dealkylation reaction can convert C9 + aromatics to toluene, benzene, mixed xylene, and light gases, and can also convert C10 + aromatics to C9 + aromatics. The reaction in the dealkylation reactor 10 can remove methyl, ethyl, propyl, butyl, and pentyl groups attached to the C10 + aromatics, as well as their isomers. In at least one embodiment, the dealkyl catalyst can be selected to convert more than 97.5 wt% of methylethylbenzene to toluene. In at least one embodiment, due to the conversion of the C9 aromatic and the removal of the methyl, ethyl, propyl, butyl, and pentyl groups attached to the C10 + aromatic, the C9 + aromatic The total conversion rate can exceed 98 wt%. The dealkylated effluent 110 can contain mixed xylene, toluene, benzene, light gas, and C9 + aromatics.

In at least one embodiment, when the hydrogen source 105 is introduced into the dealkylation reactor 10, the dealkylation reactor 10 is a fixed bed reactor and the light gas produced in the dealkylation effluent 110 is. Contains alkanes. In at least one embodiment, there is no hydrogen flow in the dealkyl reactor 10 (not shown), the dealkyl reactor 10 is a fluidized bed reactor and is produced in the dealkyl effluent 110. The light gas contains an alkene.

The dealkylated effluent 110 is introduced into the splitter unit 20.

The splitter unit 20 can be any type of separation unit capable of separating the flow into its components. In at least one embodiment, the splitter unit 20 can be a single splitter tower designed to separate the raw material stream into a plurality of separated streams. In at least one embodiment, the splitter unit 20 may have a series of splitter towers designed to separate one component from the raw material stream. In at least one embodiment, the splitter unit 20 can be one or more distillation units. In at least one embodiment, if the splitter unit 20 is a plurality of splitter towers, the splitter unit 20 includes 5 splitter towers, the first tower being between 4 bar gauge pressure (barg) and 6 barg. Operating at pressure and temperatures between 100 ° C and 200 ° C, separating the light gas from the raw materials of the first tower to produce a light gas flow 122 and the effluent of the first tower, the second tower is 0.6 barg. Operating at pressures between and 1.5 barg, and temperatures between 100 ° C and 170 ° C, it separates benzene and toluene from the first tower effluent to produce benzene / toluene flow and second tower effluent. The third tower operates at pressures between 0.3 barg and 0.9 barg, and temperatures between 70 ° C. and 150 ° C., separating benzene from the benzene / toluene stream to produce the benzene stream 126. Separating toluene from the benzene-toluene stream to produce a toluene stream 124, the fourth column operates at a pressure between 0.3 barg and 2 barg, and a temperature between 120 ° C. and 210 ° C., and the second column outflow. Separation of xylene from the material produces a mixed xylene stream 120 and C9 + aromatic stream, the fifth column operates at a pressure between 0.5 barg and 3 barg, and a temperature between 150 ° C. and 250 ° C. From the C9 + aromatic stream, the C9 aromatic is separated to produce the C9 aromatic stream 128, and from the C9 + aromatic stream, the C10 + aromatic is separated to produce the C10 + aromatic stream 132. In at least one embodiment, if the splitter unit 20 is a plurality of splitter towers, the splitter unit 20 may not have a tower that separates the C10 + aromatics from the C9 aromatics, resulting in the separation of xylene. The tower produces a xylene stream and a C9 + stream. The C9 + stream can be introduced into the alkyl exchange reactor. In at least one embodiment, if the splitter unit 20 is a plurality of splitter towers, the splitter unit 20 may not have a tower that separates the benzene / toluene flow. Those skilled in the art will appreciate that the splitter unit 20 can be designed to operate at temperatures and pressures that produce the desired flow. In at least one embodiment, if the splitter unit 20 is a single distillation column, the distillation column can include multiple compartments within a container, each compartment being a separate column described in this paragraph. It has operating conditions corresponding to each of the above.

The splitter unit 20 separates the components to produce a mixed xylene stream 120, a light gas stream 122, a toluene stream 124, a benzene stream 126, a C9 aromatic stream 128, and a C10 + aromatic stream 132. The mixed xylene stream 120 contains mixed xylene. The light gas flow 122 contains a light gas. Toluene flow 124 contains toluene. Benzene flow 126 contains benzene. The C9 aromatic stream 128 contains a C9 aromatic, which includes the C9 aromatic formed in the dealkyl reactor 10 and the unreacted C9 aromatic from the heavy modified oil feedstock 100. Includes tribes. The C10 + aromatic stream 132 contains C10 + aromatics, which include C10 + aromatics formed in the dealkylator 10 and unreacted C10 + aromatics from the heavy modified oil feedstock 100. Includes tribes. In at least one embodiment, the C10 + aromatic stream 132 can be released out of the system. In at least one embodiment, the C10 + aromatic stream 132 can be introduced into the dealkyl reactor 10 for further treatment to increase the conversion of the C10 + aromatic.

Advantageously, the separation and removal of the mixed xylene in the splitter unit increases the amount of mixed xylene produced in the alkyl exchange reactor. The absence of mixed xylene in the raw material to the alkyl exchange reactor 30 shifts the thermodynamic equilibrium of reaction 1 in the direction of xylene formation in the alkyl exchange reactor 30.

The toluene stream 124 and the C9 aromatic stream 128 are introduced into the alkyl exchange reactor 30 together with the hydrogen stream 135. The hydrogen flow 135 can be any flow containing hydrogen gas. The hydrogen stream 135 can be a stream of pure hydrogen from a fresh hydrogen source. In at least one embodiment described with reference to FIG. 2, a portion of the produced hydrogen 145 is recirculated as the hydrogen raw material 105 and introduced into the dealkyl reactor 10, and the remaining portion of the produced hydrogen is used as the hydrogen flow 135. The produced hydrogen 145 can be split so that it can be recirculated and introduced into the alkyl exchange reactor 30.

The alkyl exchange reactor 30 can be a fixed bed reactor or a fluidized bed reactor. The alkyl exchange reaction temperature in the alkyl exchange reactor 30 can be between 300 ° C and 500 ° C. The alkyl exchange reaction pressure in the alkyl exchange reactor 30 can be between 10 bar (1000 kPa) and 40 bar (4000 kPa). The liquid space velocity (LHSV) can be between ^{0.5 hr -1} and 6 hr ^-1. The operating conditions can be set to maximize the amount of xylene produced. Temperature can have a greater effect on the alkyl exchange reaction than pressure. Higher temperatures, higher pressures, and smaller LHSVs are advantageous for alkyl exchange reactions. On the other hand, higher temperatures can lead to catalyst deactivation, so operating conditions need to be balanced between maximizing production and minimizing catalyst deactivation. It is understood that there is.

The alkyl exchange reactor 30 can include an alkyl exchange reaction catalyst. The alkyl exchange reaction catalyst can include any catalyst capable of catalyzing the alkyl exchange reaction. Examples of alkyl exchange reaction catalysts include binary functional catalysts as described in US Pat. No. 9,000,247. The alkyl exchange reaction catalyst can be selected to selectively convert one or more C9 + aromatics in the alkyl exchange reaction above all else. In at least one embodiment, the alkyl exchange reaction catalyst can be selected to selectively convert trimethylbenzene to mixed xylene. When the alkyl exchange reaction occurs, the C9 + aromatics can be converted to toluene, benzene, mixed xylene, and light gases. The alkyl exchange reaction effluent 130 contains mixed xylene, toluene, benzene, light gas, and C9 + aromatics.

In at least one embodiment, the benzene stream 126 can be introduced into the alkyl exchange reactor 30, as shown in FIG. In at least one embodiment, the slip flow from the benzene flow 126 can be removed as the benzene product 326. The volume of the benzene flow 126 introduced into the alkyl exchange reactor 30 can be determined based on the desired reaction conditions within the alkyl exchange reactor 30. In at least one embodiment, the volume of benzene flow 126 introduced into the alkyl exchange reactor 30 can be controlled by the flow rate of benzene product 326. By adding benzene from the benzene stream 126 to the alkyl exchange reactor 30, the amount of benzene produced can be minimized through Reaction 2 and the amount of mixed xylene produced can be increased through Reaction 1.

The alkyl exchange reactor 30 produces an alkyl exchange reaction effluent 130. The alkyl exchange reaction effluent 130 can contain mixed xylene, toluene, benzene, light gas, and C9 + aromatics, which include C9 + aromatics formed in the alkyl exchange reactor 30 and C9 + aromatics. It contains unreacted C9 + aromatics from the heavy modified oil raw material 100.

The alkyl exchange reaction effluent 130 can be introduced into the splitter unit 20. The alkyl exchange reaction effluent 130 is separated in the splitter unit 20, and the components are mixed xylene stream 120, light gas stream 122, toluene stream 124, benzene stream 126, C9 aromatic stream 128, and C10 + aromatic stream 132. Generate a part of.

The total yield of mixed xylene in the mixed xylene stream 120 can be between 30 wt% and 89 wt%. In at least one embodiment, the total yield of mixed xylene in the mixed xylene stream 120 is 80 wt%. The total yield of toluene can be between 0 wt% and 20 wt%, or between 5 wt% and 20 wt%. The total yield of benzene can be between 0 wt% and 10 wt%, or between 1 wt% and 10 wt%. The mixed xylene stream 120 can be introduced into the isomerization unit or crystallization unit to convert m-xylene and o-xylene to p-xylene.

FIG. 2 shows an embodiment of the process of producing mixed xylene. The light gas stream 122 is introduced into the gas separator 40. The gas separator 40 can be any type of separation unit capable of separating hydrogen from the gas stream. In at least one embodiment, the gas separator 40 is a pressure swing adsorption unit. In at least one embodiment, the gas separator 40 is a hydrogen membrane separation unit. The gas separator 40 can separate the light gas flow 122 into the light gas product 140 and the produced hydrogen 145. The produced hydrogen 145 can be split to produce a hydrogen raw material 105 and a hydrogen flow 135. The light gas product 140 contains a light hydrocarbon. The produced hydrogen 145 contains hydrogen. The light gas product 140 can be released into the atmosphere, used as a fuel source, or delivered for further processing.

FIG. 4 shows an embodiment of the process of producing the mixed xylene shown in FIG. An additional aromatic stream 500 is introduced into the alkyl exchange reactor 30. The additional aromatic stream 500 can include toluene, benzene, or a combination thereof. In at least one embodiment, the additional aromatic stream 500 comprises toluene. The flow rate of the additional aromatic stream 500 shall be a volume that supplies excess toluene to improve the conversion of trimethylbenzene in the reaction between toluene and the trimethylbenzene present in the C9 aromatic stream 128. Can be done. An additional aromatic stream 500 can be used to increase the ratio of methyl groups to aromatics to 2 to improve the conversion rate of C9 aromatics to xylene. In at least one embodiment, there is no additional aromatic flow in the dealkyl reactor 10.

In at least one embodiment, the dealkylation reactor and the alkyl exchange reactor can be housed in one container. In this container, the stages of the two types of reactors are physically separated from each other so that the gas inside is not mixed. The effluent from the dealkylation reactor stage can flow out of the vessel and into the splitter unit, separating the benzene, toluene, and C9 aromatic streams within the splitter unit. It can then be reintroduced into the alkyl exchange reactor stage of the vessel.

Advantageously, the dealkylation reactor is positioned upstream of the alkyl exchange reactor to produce toluene that is not present in the heavy reforming oil feedstock, which is a reactant in the alkyl exchange reaction. Xylene is produced. Therefore, the process of having a dealkyl reactor upstream of the alkyl exchange reactor increases the amount of xylene produced. Advantageously, the dealkylation reactor is positioned upstream of the alkyl exchange reactor, which reduces the amount of C9 and C10 + aromatics to be introduced into the alkyl exchange reactor.

Methanol is absent in both the dealkyl and alkyl exchange reactors, and there is no methylation reaction, which is an irreversible reaction that adds a methyl group to a compound. In at least one embodiment, the heavy modified oil feedstock is free of ethylbenzene.

(Example)
The following examples were carried out in laboratory equipment.

(Example 1)
Example 1 is an analytical study of the dealkyl reactor 10 shown in FIG. The heavy reforming oil raw material 100 had the composition shown in Table 1. The hydrogen raw material 105 was recirculated from the produced hydrogen 145 after recovery from the gas separator 40.

The dealkyl reactor 10 had a temperature of 400 ° C. and a pressure of 30 bar (3000 kPa). The weight space velocity (whsv) was 4.2 / hour (hr ^-1 ). The ratio of hydrogen gas (H ₂ ) to hydrocarbon was 4: 1 (mol / mol). The catalyst was a ZSM-5 catalyst designed for dealkylation reactions that selectively convert methylethylbenzene to toluene, benzene, and light alkanes. The composition of the dealkylated effluent 110 is shown in Table 2.

The conversion of methylethylbenzene in the dealkyl reactor 10 was 98.8 wt%. The conversion of trimethylbenzene in the dealkyl reactor 10 was 10.9 wt%.

(Example 2)
Example 2 is an analytical study of the alkyl exchange reactor 30 shown in FIG. The combined raw materials for the alkyl exchange reactor 30 had the compositions shown in Table 3.

The alkyl exchange reactor 30 had a temperature of 400 ° C. and a pressure of 30 bar (3000 kPa). The whisv was ^{4.2 hr -1.} The ratio of hydrogen gas (H ₂ ) to hydrocarbons is 4: 1 (mol / mol). The catalyst was an alkyl exchange reaction catalyst with zeolite. The composition of the alkyl exchange reaction effluent 130 is shown in Table 4.

The conversion of trimethylbenzene in the alkyl exchange reactor 30 was 56 wt%. The conversion of toluene in the alkyl exchange reactor 30 was 52 wt%.

(Example 3)
Example 3 was a comparative example of a single reactor system. In this case, the dealkylation reaction and the alkyl exchange reaction occur in the same reactor. The reactor was coupled to the splitter unit described with reference to FIGS. 5 and 2. The heavy reforming oil raw material 100 having the composition shown in Table 5 was introduced into the alkyl exchange reaction-dealkyl reactor 60 together with the hydrogen raw material 105. The hydrogen raw material 105 was simulated as a raw material from a hydrogen source of a refinery containing only hydrogen.

The alkyl exchange-dealkyl reactor 60 was operated at a temperature of 400 ° C., a pressure of 20 bar, a whisv of 4.2 hr- ¹ , and a hydrogen to hydrocarbon ratio of 4: 1. The catalyst was a catalyst in which 40% was beta and 60% was MCM-41, which could promote both the alkyl exchange reaction and the dealkylation reaction.

The single reactor effluent 610 was introduced into the splitter unit 20. The splitter unit 20 operated to separate the single reactor effluent 610 into its constituents shown in Table 6. The light product 622 was introduced into the gas separator 40. The gas separator 40 separated hydrogen from the light hydrocarbon to produce 145 produced hydrogen and 640 gas product containing the light hydrocarbon.

The yield of mixed xylene was 34 wt%. This yield was within the range of xylene yields for single reactor systems between 32 wt% and 35 wt%. In a single reactor system, the amount of xylene produced is limited by the thermodynamic equilibrium shown in Reaction 1. The conversion of methylethylbenzene was 80%. This conversion rate falls within the range of typical conversion rates of methylethylbenzene in single reactor systems between 80 wt% and 92 wt%. The conversion rate of trimethylbenzene was 45%. This yield was slightly outside the typical conversion rate range for trimethylbenzene, which was around 50 wt%.

(Example 4)
Example 4 was a simulation of the process of producing the mixed xylene shown in FIGS. 6 and 2. The heavy reforming oil raw material 100 having the composition shown in Table 7 is introduced into the dealkylation reactor 10 together with the hydrogen raw material 105. The flow rate of the hydrogen raw material 105 was 138.6 kg / hr, and contained 66.5 kg / hr of hydrogen gas and 72.0 kg / hr of light hydrocarbons.

The dealkyl reactor 10 had a temperature of 400 ° C. and a pressure of 30 bar (3000 kPa). The whisv was ^{4.2h -1.} The ratio of hydrogen gas (H ₂ ) to hydrocarbon was 4: 1 (mol / mol). The catalyst was a three-dimensional zeolite-based dealkyl catalyst. The composition of the dealkylated effluent 110 is shown in Table 8.

The dealkylated effluent 110 was introduced into the splitter unit 20. The splitter unit 20 separated the dealkylated effluent 110 into its constituents. The light gas stream 122 was introduced into the gas separator 40 to produce the light gas product 140 and the produced hydrogen 145. The produced hydrogen 145 was split to generate a hydrogen slip flow 245 and a hydrogen flow 135. The composition and flow rate are shown in Table 9.

A benzene stream 126, a toluene stream 124, and a C9 aromatic stream 128 were introduced into the alkyl exchange reactor 30 along with an additional aromatic stream 500 and a hydrogen stream 135. The flow rate of the additional aromatic stream 500 was 70.0 kg / hr of pure toluene. This toluene produces an excess of toluene in the alkyl exchange reactor 30. The alkyl exchange reactor 30 had a temperature of 400 ° C. and a pressure of 30 bar (3000 kPa). The whisv was ^{4.2h -1.} The ratio of hydrogen gas (H ₂ ) to hydrocarbons is 4: 1 (mol / mol). The catalyst was a one-dimensional zeolite-based alkyl exchange reaction catalyst. The alkyl exchange reaction catalyst was not the same as the dealkylation catalyst. The composition of the various streams is shown in Table 10.

The amount of mixed xylene produced in Example 4 was 814.5 kg / hr. The total conversion of trimethylbenzene and methylethylbenzene was 100%.

(Example 5)
Example 5 was a simulation of the process of producing the mixed xylene shown in FIG. The heavy reforming oil raw material 100 having the composition shown in Table 11 was introduced into the dealkylation reactor 10 together with the hydrogen raw material 105. The flow rate of the hydrogen raw material 105 was 138.6 kg / hr, and contained 66.5 kg / hr of hydrogen gas and 72.0 kg / hr of light hydrocarbons.

The dealkyl reactor 10 had a temperature of 400 ° C. and a pressure of 30 bar (3000 kPa). The whisv was ^{4.2 hr -1.} The ratio of hydrogen gas (H ₂ ) to hydrocarbon was 4: 1 (mol / mol). The catalyst was a three-dimensional zeolite-based dealkyl catalyst. The composition of the dealkylated effluent 110 is shown in Table 12.

The dealkylated effluent 110 was introduced into the splitter unit 20. The splitter unit 20 separated the dealkylated effluent 110 into its constituents. The light gas stream 122 was introduced into the gas separator 40 to produce the light gas product 140 and the produced hydrogen 145. The produced hydrogen 145 was split to generate a hydrogen slip flow 245 and a hydrogen flow 135. The composition and flow rate are shown in Table 13.

A benzene stream 126, a toluene stream 124, and a C9 aromatic stream 128 were introduced into the alkyl exchange reactor 30 without excess toluene. Hydrogen flow 135 was introduced into the alkyl exchange reactor 30. The alkyl exchange reactor 30 had a temperature of 400 ° C. and a pressure of 30 bar (3000 kPa). The whisv was ^{4.2h -1.} The ratio of hydrogen gas (H ₂ ) to hydrocarbons is 4: 1 (mol / mol). The catalyst was a one-dimensional zeolite-based alkyl exchange reaction catalyst. The alkyl exchange reaction catalyst was not the same as the dealkylation catalyst. The composition of the various streams is shown in Table 14.

The amount of mixed xylene produced in Example 5 was 755.7 kg / hr. The conversion of trimethylbenzene in the alkyl exchange reactor 30 was 51 wt%. The total conversion of trimethylbenzene from the heavy reforming oil raw material 100 to the mixed xylene flow 120 is 100 wt%. In other words, all trimethylbenzene in the heavy reforming oil raw material 100 is converted to xylene in the mixed xylene stream 120.

Comparing the amounts of mixed xylene produced in Example 4 and Example 5, it is shown that the improvement in yield is due to the addition of excess toluene to the alkyl exchange reactor 30.

(Example 6)
Example 6 was a simulation of the process of producing the mixed xylene shown in FIG. The heavy reforming oil raw material 100 having the composition shown in Table 15 was introduced into the dealkylation reactor 10 together with the hydrogen raw material 105. The flow rate of the hydrogen raw material 105 was 138.6 kg / hr, and contained 66.5 kg / hr of hydrogen gas and 72.0 kg / hr of light hydrocarbons.

The dealkyl reactor 10 had a temperature of 400 ° C. and a pressure of 30 bar (3000 kPa). The whisv was ^{4.2 hr -1.} The ratio of hydrogen gas (H ₂ ) to hydrocarbon was 4: 1 (mol / mol). The catalyst was a three-dimensional zeolite-based dealkyl catalyst. The composition of the dealkylated effluent 110 is shown in Table 16.

The dealkylated effluent 110 was introduced into the splitter unit 20. The splitter unit 20 separated the dealkylated effluent 110 into its constituents. The light gas stream 122 was introduced into the gas separator 40 to produce the light gas product 140 and the produced hydrogen 145. The produced hydrogen 145 was split to generate a hydrogen slip flow 245 and a hydrogen flow 135. The composition and flow rate are shown in Table 17.

Benzene flow 126 and toluene flow 124 were introduced into the alkyl exchange reactor 30 without excess toluene. Hydrogen flow 135 was introduced into the alkyl exchange reactor 30. The C9 aromatic slip stream 228 was separated from the C9 aromatic stream 128 and the remaining C9 aromatic stream 128 was introduced into the alkyl exchange reactor 30. The C9 aromatic slip flow 228 was adjusted to maintain the ratio of methyl to the aromatic ring in the alkyl exchange reactor 30 in the absence of additional aromatic flow at 2. The alkyl exchange reactor 30 had a temperature of 400 ° C. and a pressure of 30 bar (3000 kPa). The whisv was ^{4.2h -1.} The ratio of hydrogen gas (H ₂ ) to hydrocarbons is 4: 1 (mol / mol). The catalyst was a one-dimensional zeolite-based alkyl exchange reaction catalyst. The alkyl exchange reaction catalyst was not the same as the dealkylation catalyst. The composition of the various streams is shown in Table 18.

The amount of mixed xylene produced in Example 6 was 650.3 kg / hr. The total conversion of trimethylbenzene is 80 wt%.

Comparing the production rates of mixed xylene in Example 5 and Example 6 shows that the amount of mixed xylene produced increases when the total flow rate of the C9 aromatic stream is introduced into the alkyl exchange reactor.

(Example 7)
Example 7 was a comparative example in which the splitter unit was not present between the dealkyl reactor and the alkyl exchange reactor shown in FIG. The heavy reforming oil raw material 100 having the composition shown in Table 19 was introduced into the dealkyl reactor 10 together with the hydrogen raw material 105. The flow rate of the hydrogen raw material 105 was 138.6 kg / hr, and contained 66.5 kg / hr of hydrogen gas and 72.0 kg / hr of light hydrocarbons.

The dealkyl reactor 10 had a temperature of 400 ° C. and a pressure of 30 bar (3000 kPa). The whisv was ^{4.2 hr -1.} The ratio of hydrogen gas (H ₂ ) to hydrocarbon was 4: 1 (mol / mol). The catalyst was a three-dimensional zeolite-based dealkyl catalyst. The composition of the dealkylated effluent 110 is shown in Table 20.

The dealkylated effluent 110 was introduced into the alkyl exchange reactor 30. The alkyl exchange reactor 30 had a temperature of 400 ° C. and a pressure of 30 bar (3000 kPa). The whisv was ^{4.2h -1.} The ratio of hydrogen gas (H ₂ ) to hydrocarbons is 4: 1 (mol / mol). The catalyst was a one-dimensional zeolite-based alkyl exchange reaction catalyst. The alkyl exchange reaction catalyst was not the same as the dealkylation catalyst. The alkyl exchange reaction product 930 was introduced into the splitter unit 20. The splitter unit 20 contains the alkyl exchange reaction product 930 as its constituents: mixed xylene fraction 920, light gas fraction 922, toluene fraction 924, benzene fraction 926, C9 aromatic fraction 928, and C10 + aromatic. Separated into tribal fractions 932. The composition of the various streams is shown in Table 21.

The amount of mixed silene produced was 405.8 kg / hr. The total conversion of trimethylbenzene is 72 wt%.

Comparing the mixed xylene production rates of Example 4 and Example 7, the addition of a process flow configuration change associated with the splitter unit unexpectedly and advantageously increased the mixed xylene production rate by about 100%. You can see that there is.

Although embodiments of the invention have been described in detail, it should be appreciated that various modifications, substitutions, and modifications can be made without departing from the principles and scope of the invention. Therefore, the scope of the embodiments of the present invention should be determined by the following claims and their appropriate legal equivalents.

Unless otherwise indicated, the various elements described herein may be used in combination with any other element described.

The singular forms "a (one)", "an (one)", and "the (this)" also include multiple referents, unless the context clearly dictates otherwise.

"Optional" or "as needed" means that the events or situations described below may or may not occur. This description includes cases where an event or situation occurs and cases where it does not occur.

In the present specification, the range may be expressed from one specific approximate value to another specific approximate value, but is comprehensive unless otherwise specified. When the above range notation is made, it should be understood that another embodiment is from one particular value to another, in addition to all combinations within the above range.

If patents or publications are referenced throughout this application, the disclosure of these references is to make these references in the description herein in order to more fully describe the prior art to which the invention relates. It is intended to be incorporated herein by reference in its entirety, provided that there is no conflict.

As used herein and in the appended claims, the words "comprise,""has," and "include," and all of their grammatical variants, are used. , Each of which is intended to have an open, non-limiting meaning without excluding additional elements or steps.

Claims (26)

A method for producing mixed xylene from heavy-duty reformed oil raw materials.
In the step of introducing the heavy reforming oil raw material and the hydrogen raw material into the dealkylating reactor, the dealkylating reactor contains a dealkylating catalyst, and the heavy reforming oil contains toluene and nine or more. The step and the step, which contains an aromatic hydrocarbon (C9 + aromatic) having a carbon atom, and the hydrogen raw material contains hydrogen gas,
In the dealkyl reactor, in the presence of the dealkyl catalyst, the heavy reforming oil raw material is reacted with the hydrogen gas to produce a dealkyl effluent, which is a step of producing the dealkyl effluent. Is at the dealkylation temperature, the dealkylation reactor is at the dealkylation pressure, and the dealkylation reactor has a liquid space velocity.
A step of introducing the dealkylated effluent into a splitter unit, wherein the dealkylated effluent comprises a light gas, toluene, benzene, mixed xylene, and a C9 + aromatic.
The step of separating the dealkylated effluent into a light gas stream, a toluene stream, a benzene stream, a C9 aromatic stream, a C10 + aromatic stream, and a mixed xylene stream in the splitter unit, wherein the light gas stream is , The toluene stream contains toluene, the benzene stream contains benzene, the mixed xylene stream contains mixed xylene, the C9 stream contains C9 aromatics, said C10 +. Aromatic flow, including C10 + aromatic, step and
A step of introducing the toluene stream, the C9 aromatic stream, and the hydrogen stream into an alkyl exchange reactor, wherein the alkyl exchange reactor comprises an alkyl exchange reaction catalyst, and the hydrogen stream comprises hydrogen gas. Steps and
The step of reacting the toluene stream and the C9 aromatic stream in the presence of the alkyl exchange reaction catalyst to produce an alkyl exchange reaction effluent, wherein the alkyl exchange reactor is at the alkyl exchange reaction temperature. The alkyl exchange reactor is at an alkyl exchange reaction pressure and the alkyl exchange reactor has a liquid space rate, with steps.
A step of introducing the alkyl exchange reaction effluent into the splitter unit, wherein the alkyl exchange reaction effluent comprises light gas, toluene, benzene, mixed xylene, and a C9 + aromatic.
A step of separating the alkyl exchange reaction effluent in the splitter unit so that the mixed xylene in the alkyl exchange reaction effluent flows out of the splitter unit as part of the mixed xylene flow.
How to prepare. The method according to claim 1, wherein the heavy reforming oil raw material contains 0% by weight to 60% by weight of toluene. The step of introducing the light gas flow into the gas separator and
A step of separating the light gas flow into produced hydrogen and a light gas product,
The method according to claim 1, further comprising. The method according to claim 3, wherein the gas separator includes a pressure swing adsorption unit. The method of claim 1, further comprising the step of introducing the benzene stream into the alkyl exchange reactor. The method of claim 1, further comprising supplying the alkyl exchange reactor with an additional aromatic stream so that there is excess toluene for the alkyl exchange reaction in the alkyl exchange reactor. The method of claim 1, wherein the dealkylation temperature is between 200 ° C and 500 ° C. The method of claim 1, wherein the dealkylation pressure is between 5 bar and 40 bar. The method of claim 1, wherein the liquid space velocity in the dealkyl reactor is ^{between 1 hr -1} and 10 hr -1. The method of claim 1, wherein the alkyl exchange reaction temperature is between 300 ° C and 500 ° C. The method of claim 1, wherein the alkyl exchange reaction pressure is between 10 bar and 40 bar. The method of claim 1, wherein the liquid space velocity in the alkyl exchange reactor is ^{between 0.5 hr -1} and 6 hr ^-1. The method of claim 1, wherein the total yield of mixed xylene in the mixed xylene stream is between 30 wt% and 89 wt%. A method for producing mixed xylene from heavy-duty reformed oil raw materials.
In the step of introducing the heavy reforming oil raw material and the hydrogen raw material into the dealkylating reactor, the dealkylating reactor contains a dealkylating catalyst, and the heavy reforming oil contains 9 or more carbon atoms. Aromatic hydrocarbon (C9 + aromatic) having, said hydrogen raw material contains hydrogen gas, step and
In the dealkyl reactor, in the presence of the dealkyl catalyst, the heavy reforming oil raw material is reacted with the hydrogen gas to produce a dealkyl effluent, which is a step of producing the dealkyl effluent. Is at the dealkylation temperature, the dealkylation reactor is at the dealkylation pressure, and the dealkylation reactor has a liquid space velocity.
A step of introducing the dealkylated effluent into a splitter unit, wherein the dealkylated effluent comprises light gas, toluene, benzene, mixed xylene, and a C9 + aromatic, the splitter unit comprising a plurality of splitter towers. , Steps and
The step of separating the dealkylated effluent into a light gas stream, a toluene stream, a benzene stream, a C9 aromatic stream, a C10 + aromatic stream, and a mixed xylene stream in the splitter unit, wherein the light gas stream is , The toluene stream contains toluene, the benzene stream contains benzene, the mixed xylene stream contains mixed xylene, the C9 stream contains C9 aromatics, said C10 +. Aromatic flow, including C10 + aromatic, step and
A step of introducing the toluene stream, the C9 aromatic stream, and the hydrogen stream into an alkyl exchange reactor, wherein the alkyl exchange reactor comprises an alkyl exchange reaction catalyst, and the hydrogen stream comprises hydrogen gas. Steps and
The step of reacting the toluene stream and the C9 aromatic stream in the presence of the alkyl exchange reaction catalyst to produce an alkyl exchange reaction effluent, wherein the alkyl exchange reactor is at the alkyl exchange reaction temperature. The alkyl exchange reactor is at an alkyl exchange reaction pressure and the alkyl exchange reactor has a liquid space rate, with steps.
A step of introducing the alkyl exchange reaction effluent into the splitter unit, wherein the alkyl exchange reaction effluent comprises light gas, toluene, benzene, mixed xylene, and a C9 + aromatic.
A step of separating the alkyl exchange reaction effluent in the splitter unit so that the mixed xylene in the alkyl exchange reaction effluent flows out of the splitter unit as part of the mixed xylene flow.
How to prepare. The step of introducing the light gas flow into the gas separator and
A step of separating the light gas flow into produced hydrogen and a light gas product,
14. The method of claim 14. 15. The method of claim 15, wherein the gas separator is a pressure swing adsorption unit. 14. The method of claim 14, further comprising the step of introducing the benzene stream into the alkyl exchange reactor. 14. The method of claim 14, further comprising supplying the alkyl exchange reactor with an additional aromatic stream so that there is excess toluene for the alkyl exchange reaction in the alkyl exchange reactor. 14. The method of claim 14, wherein the dealkylation temperature is between 200 ° C and 500 ° C. 14. The method of claim 14, wherein the dealkylation pressure is between 5 bar and 40 bar. 14. The method of claim 14, wherein the liquid space velocity in the dealkyl reactor is ^{between 1 hr -1} and 10 hr -1. The step of separating the dealkylated effluent is
The step of introducing the dealkylated effluent into the first column and
A step of separating the dealkali effluent in the first tower to generate the light gas flow and the first effluent.
The step of introducing the effluent from the first tower into the second tower,
A step of separating the 1st column effluent in the 2nd column to generate a benzene / toluene flow and a 2nd column effluent.
The step of introducing the benzene / toluene flow into the third column and
A step of separating the benzene / toluene flow in the third column to generate the benzene flow and the toluene flow, and
The step of introducing the second tower effluent into the fourth tower and
A step of separating the second tower effluent in the fourth tower to generate the mixed xylene stream and the C9 + aromatic stream.
The step of introducing the C9 + aromatic stream into the 5th tower,
A step of separating the C9 + aromatic stream in the fifth tower to generate the C9 aromatic stream and the C10 + aromatic stream.
14. The method of claim 14. 14. The method of claim 14, wherein the alkyl exchange reaction temperature is between 300 ° C and 500 ° C. 14. The method of claim 14, wherein the alkyl exchange reaction pressure is between 10 bar and 40 bar. 14. The method of claim 14, wherein the liquid space velocity in the alkyl exchange reactor is ^{between 0.5 hr -1} and 6 hr ^-1. The method of claim 14, wherein the total yield of the mixed xylene in the mixed xylene stream is between 30 wt% and 89 wt%.

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